E4. Corey, Gerald E. "How to Improve Your Tuning on the Bassoon."
The Journal of the International Double Reed Society 8 (1980):
32.

"This fingering is excellent, but sometimes breaks on attacks":

Eb
x o x | x x x
c#

"This is beautifully in tune and is used by many famed players. It
has the disadvantage in being brighter and more metallic in tone color
than surrounding notes, but this can be compensated for by reed trim and
embouchure adjustment":